Mary Regan has witnessed a transformation outside the front door of her Union Square office in Somerville — new “corrals” provide more parking spaces for bicyclists, angled parking has replaced parallel parking for cars to keep doors from flying open into bicycle lanes, and those lanes have been freshly painted.

At the nearby farmers’ market, $1 in food stamps is worth $2 in produce to help low-income customers afford fresh fruits and vegetables.

“I’ve heard people here say that farmers’ markets used to seem like an elite, foreign thing,” said Regan, a community organizer at a nonprofit organization for affordable housing. “But now that they can use their [food stamps] and get twice as much for the same amount of money, they are buying more healthy foods.”

A decade after an ambitious experiment dubbed Shape Up Somerville was launched to lower obesity rates in elementary school children, the campaign has been expanded and woven into the fabric of everyday life in this diverse city of 78,000, where 52 languages are spoken in the public schools and almost two-thirds of students come from families so poor that they receive free or reduced-price school lunches.

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City decisions about roads, bridges, other transportation projects, real estate development, and parks include an analysis of how the plans might affect residents’ physical activity or ability to shop for healthy food. Two city employees ensure healthy goals are considered at every step, particularly by collaborating with community groups.

Restaurants that meet specific nutrition standards win a Shape Up Somerville sign for their door and campaign logo to display on the menu items that pass muster. So far 40 of the city’s 200 eateries have notched that distinction.

At Mr. Crepe in Davis Square, a Shape Up Somerville menu is displayed prominently behind the counter, featuring crepes with vegetables and lean meats. Absent are those filled with chocolate and Nutella. “I wish they had this everywhere,” said Angela Borges, 28, of Watertown, who stopped in one day last week while getting her bike repaired. “Someone already did the work for you to say which were the healthiest items.”

But measuring whether the trail-blazing initiative has, in fact, lowered the city’s obesity rates and improved health is a much trickier proposition, in Somerville, as well as in the dozens of communities nationwide that are receiving federal and private grants to try to replicate Somerville’s early success.

Tufts University researchers, collaborating with Somerville in 2002 for a three-year study, found that boosting whole grains, fruits, and vegetables in school, adding physical activities during and after school, running family nutrition forums and sponsoring many community-wide fitness events helped 8-year-old children gain, on average, one pound less during the school year than children from two similar communities who did not participate in the program.

The results were considered significant because nearly half of Somerville's youngsters in first through third grade at that time were overweight or at risk of being overweight, so even the modest weight loss translated into large numbers of children moving out of that category.

But the researchers have not published any other results, so it’s hard to know how lasting the intervention was.

Their study was funded, in part, by the federal Centers for Disease Control and Prevention, which has since handed out roughly $600 million in grants to dozens of states and communities nationwide for similar community-level programs to combat obesity and related chronic ailments such as heart disease and diabetes.

Rebecca Bunnell, acting director of the agency’s Division of Community Health, said it is just starting a five-year project to more closely evaluate the effectiveness of some of the local programs.

“We know at the individual level, people who use public transportation or bicycle will lower their weight and that is something we have proven in several studies across the country,” Bunnell said.

But measuring the effectiveness of these types of programs, which worked for much smaller groups of individuals, is much more challenging when attempted across an entire community involving thousands of people, Bunnell said. It is difficult on this scale to have a control group, which is considered a gold standard for scientific studies. Giving one community resources for programs, and withholding funds from another similarly-matched one over a period of years specifically to compare the outcomes, could raise ethical questions, she said.

“What we’re trying to do at the community level is to create the environment that supports individual changes and make options available for people to be healthy,” Bunnell said.

Massachusetts, which last year received CDC grants totalling about $15 million over five years, intends to measure outcomes in some of the 52 communities it awarded the money for anti-obesity and related programs, said Cheryl Bartlett, director for community health and prevention at the state Department of Public Health.

Bartlett said the agency plans to collect data on emergency room visits and hospitalizations in communities that received the grants and compare them with what happens in similar places that didn’t. Researchers will also regularly survey residents in the grant communities about their health and awareness of the programs.

The goal is to reduce obesity, heart disease, and tobacco use by a collective 5 percent across the 52 communities, she said. The 52 represent about a third of the state’s population.

Somerville is among the 52, and will receive $60,000 a year. There are signs that the city’s decadelong head start has started to bear fruit.

An annual health survey found a significant decrease in the percentage of Somerville adults reporting high blood pressure between 2002 and 2008, the most recent data available, while statewide rates rose. The survey found slight increases among those reporting diabetes and high cholesterol in Somerville, but the rate of increase was substantially slower than it was statewide.

On the exercise front, the percentage of Somerville adults who reported regular moderate or vigorous physical activity jumped significantly between 2002 and 2010.

“I bike around Somerville a ton, and I appreciate the demarcations on the road to say, ‘A bike belongs here too,’ ” said Sophia DeVito, 23, while leaving her bike in a corral near Davis Square. She does not own a car and bikes about 8 to 10 hours each week.

Also noteworthy is a sharp drop in the percentage of middle- and high-schoolers who reported drinking sugary beverages. The percentages of Somerville adults who reported they were overweight or obese rose slightly since 2002, but the levels are below statewide figures.

Virginia Chomitz, an assistant professor at Tufts University School of Medicine who is tracking Somerville's progress, said that while researchers can’t conclusively say the improved exercise and health outcomes are due to the city’s Shape Up Somerville program, it is reasonable to believe they are linked.

“There’s still a whole lot to learn about how this all works out, but we have every reason to think that this is the right way to go,” Chomitz said.

Somerville Mayor Joseph Curtatone said his city has aggressively sought federal and private grants to fuel its anti-obesity mission. Among the grants was $100,000 a year over four years awarded by the Robert Wood Johnson Foundation.

“Much of what we do is not costly,” said Curtatone, who has championed his city’s program nationally. “Without money you can be out mobilizing the community to tap resources and expertise that don’t necessarily come from the city budget.”

The obesity epidemic took years to evolve, and will take time to conquer, Curtatone said. “We feel we need to make a commitment for the long-term,” he said.

Globe correspondent Helen Shen contributed to this story. Kay Lazar can be reached at klazar@globe.com. Follow her on Twitter @GlobeKayLazar.

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